Over the past 10 to 15 years, researchers have observed substantial growth in the SSI caseload due to increases in the numbers of immigrants who receive benefits (Ross, 1995; Rector, 1996). Moreover, previous research that uses 1980 and 1990 U.S. census data shows that immigrants receive SSI at higher rates than do natives, and that this differential remains even when differences in age structure, disability, poverty and a number of other social variables are taken into account (Bean, Van Hook, and Glick, 1996). The primary concern of the proposed research is to disclose the determinants of both the absolute and relative growth in SSI receipt among elderly and disabled immigrants compared to natives using 1980 and 1990 census data, the 1994 and 1995 March Current Population Survey (CPS) data files and recent panels of the Survey of Income and Program Participation (SIPP). The research specifically aims to explain immigrant/native differentials and changes over time in terms of differences in characteristics relating directly to eligibility for SSI (age, disability, income and assets), differences in characteristics leading both directly and indirectly to SSI receipt including the availability of alternative means of support (Social Security receipt, home ownership, intragenerational wealth transfers, human capital variables), and differences in the propensity to use welfare that may be detected within communities of immigrants. Because immigrants do not comprise a homogeneous group, the research will discern the patterns of determinants among various country-of-origin and period-of-entry immigrant cohorts.